Cu- and S-Doped Heteropolyacid Co₂Mo₁₀ as Electrocatalysts for Efficient Hydrogen Evolution

This study employed polyoxometalate Co₂Mo₁₀ as a precursor and a two-step method to prepare carbon cloth-supported Cu_<i>x</i>S-CoS₂-MoS₂ materials. The morphology and structure of the materials were characterized using XRD, XPS, SEM, TEM, and other techniques. Interestingly, changes in the reducing gas during the calcination process could adjust the product morphology, thereby altering catalytic activity. Electrochemical results indicated that the Cu_<i>x</i>S-CoS₂-MoS₂ nanomaterials prepared under an NH₃ atmosphere exhibited unique morphology and structural advantages. They demonstrated significant electrocatalytic activity for the hydrogen evolution reaction (HER) in alkaline and acidic electrolytes (overpotentials of 108 and 196 mV at a current density of 10 mA cm^-2, lower than the overpotentials of 143 and 226 mV obtained under a H₂-Ar atmosphere during calcination) and excellent long-term durability. These findings provide insights and methods for synthesizing multicomponent electrocatalysts with enhanced catalytic performance.